diff --git a/app/src/main/java/de/jeanlucmakiola/calendula/data/calendar/TimeBridge.kt b/app/src/main/java/de/jeanlucmakiola/calendula/data/calendar/TimeBridge.kt
new file mode 100644
index 0000000..757c7a8
--- /dev/null
+++ b/app/src/main/java/de/jeanlucmakiola/calendula/data/calendar/TimeBridge.kt
@@ -0,0 +1,7 @@
+package de.jeanlucmakiola.calendula.data.calendar
+
+import kotlin.time.Instant
+
+fun Long.toKotlinInstantFromEpochMillis(): Instant = Instant.fromEpochMilliseconds(this)
+
+fun Instant.toEpochMillis(): Long = toEpochMilliseconds()
diff --git a/app/src/test/java/de/jeanlucmakiola/calendula/data/calendar/TimeBridgeTest.kt b/app/src/test/java/de/jeanlucmakiola/calendula/data/calendar/TimeBridgeTest.kt
new file mode 100644
index 0000000..08de313
--- /dev/null
+++ b/app/src/test/java/de/jeanlucmakiola/calendula/data/calendar/TimeBridgeTest.kt
@@ -0,0 +1,26 @@
+package de.jeanlucmakiola.calendula.data.calendar
+
+import com.google.common.truth.Truth.assertThat
+import kotlin.time.Instant
+import org.junit.jupiter.api.Test
+
+class TimeBridgeTest {
+
+    @Test
+    fun `epoch millis round-trips through Instant`() {
+        val original = 1_717_840_800_000L // 2024-06-08T10:00:00Z
+        val instant = original.toKotlinInstantFromEpochMillis()
+        assertThat(instant.toEpochMillis()).isEqualTo(original)
+    }
+
+    @Test
+    fun `zero millis maps to Instant epoch`() {
+        assertThat(0L.toKotlinInstantFromEpochMillis()).isEqualTo(Instant.fromEpochMilliseconds(0L))
+    }
+
+    @Test
+    fun `negative epoch millis is supported`() {
+        val original = -1_000_000L
+        assertThat(original.toKotlinInstantFromEpochMillis().toEpochMillis()).isEqualTo(original)
+    }
+}
diff --git a/fdroid-metadata/de.jeanlucmakiola.calendula/de/full_description.txt b/fdroid-metadata/de.jeanlucmakiola.calendula/de-DE/full_description.txt
similarity index 100%
rename from fdroid-metadata/de.jeanlucmakiola.calendula/de/full_description.txt
rename to fdroid-metadata/de.jeanlucmakiola.calendula/de-DE/full_description.txt
diff --git a/fdroid-metadata/de.jeanlucmakiola.calendula/de/short_description.txt b/fdroid-metadata/de.jeanlucmakiola.calendula/de-DE/short_description.txt
similarity index 100%
rename from fdroid-metadata/de.jeanlucmakiola.calendula/de/short_description.txt
rename to fdroid-metadata/de.jeanlucmakiola.calendula/de-DE/short_description.txt